Arduino and Raspberry Pi are often mentioned in the same breath, but they serve different purposes.
Arduino is a microcontroller — ideal for reading sensors, controlling motors, and running simple, repetitive tasks without an operating system. It’s low-power, instant-on, and perfect for embedded systems.
Raspberry Pi is a full-fledged single-board computer. It runs an operating system, handles multitasking, and can manage complex projects like home servers, media centres, or AI experiments.
Think of Arduino as a skilled specialist and Raspberry Pi as a versatile generalist. Many advanced projects use both — the Pi handles high-level logic, while the Arduino interfaces directly with hardware.